I need to build a pad for a 22kW generator I am installing for my house. The image shows the situation. This generator is quite heavy. I plan to pour a rebar reinforced 6" pad for it.
My question is--what to do to fill/retain the area in green? I am guessing this area will be ~18-24" deep at the large end. Because the generator is so heavy, I am tempted to just make the whole thing concrete---but I am afraid doing so will make it tend to slide off of the hill. What is the best approach to ensure that does not happen? Drive rebar into the hill vertically 18" deep 1ft o.c.? or is there an easier/cheaper solution?